This invention relates to portable hair dryers used in close proximity to the user's hair. More specifically, this invention relates to axial fan driven portable hair dryers with means for preventing hair entanglement of the user when the hair dryer is used in close proximity with the hair, such as during a styling or drying maneuver.
In the past, most electrically heated forced-air hair dryers included a transverse flow fan when used with styling attachments such as a comb or a brush. Axial fan hair dryers when used with attachments were typically bulky in nature and inconvenient to use.
If a more compact design of a portable axial fan hair dryer with or without attachments was desirable, a problem resulted in that the working end would be within a few inches of the axial fan. This may result in hair entanglement through the air inlet of the hair dryer.
The prevention of hair entanglement through the air inlet may be somewhat helped by including a mesh screen over the air inlet. However, the mesh may not be too fine since it will cause lint or the like to clog up the air inlet screen and thus restrict air flow causing the unit to overheat.
When a compact hair dryer, with a relatively short air flow portion, is used with or without styling implements, the hair of the user may readily enter through the air inlet portion of the hair dryer either when still attached to the user's head or as separate pieces of hair. The aerodynamics of the hair dryer system and the presenting of the center of rotation of the axial fan very proximate the air inlet is believed to create hair entanglement problems more serious than those associated with a transverse flow hair dryer used with styling attachments.
There are two basic types of hair entanglement problems which will effect the operation of the hair dryer and/or the safety or ease of use of the hair dryer. The first type deals with hair entanglement when the hair remains attached to the user's head. If hair enters through the air inlet portion of the hair dryer, the hair strands may engage the fan shaft or its associated bearing and result in the fan stalling. Such an entanglement may cause the user to be pulled toward the dryer, and if the fan stalls, a situation may momentarily exist where the user is attached to the hair dryer and the heat of the hair dryer is increasing.
Another hair entanglement problem occurs when hair strands of the user enter through the air inlet in front of the fan. Because the center of rotation of the axial fan faces the air inlet, the hair strands tend to find the center of the system and start to twist. If such a twisting occurs among several strands, the hair may become twisted together and form a knot inside the screen thus causing the user to either pull free or cut the entangled hair.
Further problems result when loose hair falls into the air inlet portion through the screen. These loose hairs may eventually wrap around the shaft beneath the fan until they fill up whatever space is available. When the loose hair builds up, the fan may slow down and cause an associated thermostat to open which ultimately may result in consumer dissatisfaction and excessive returns.
These prior art difficulties have been substantially overcome by providing a compact axial fan hair dryer suitable for use as a dryer or styler in close proximity to the hair. The hair dryer includes a stationary guard or shield assembly in the air inlet portion of the hair dryer and a collar affixed to the downstream portion of the fan blades and disposed about the motor.